This article reviews the theoretical and political history of the concept of precarity, used to describe various forms of insecurities, primarily those related to conditions of labor, employment, and wage. Precarity and the related neologism precariat have recently gained ground in Anglophone intellectual and political discussions. It is the premise of the article that, with an increasingly globalized economy, discussions and movement action based on precarity may be of growing importance in a Danish context. The aim of the article is to show how the history of these concepts has unfolded in sociological discussions and social movement practices since the turn of the century. I begin with the sociological discussion about the concept of the precariat, a class formation based on the conditions and experiences of precarity. I then show how the concept of precarity has a history in activist thought beyond these sociological discussions and how social movements, based on this thought, throughout the 2000s have mobilized around the concept, primarily in the so-called EuroMayDay parades. In the last section, I discuss how the economic crisis has affected social movement practices and how labor unions have begun paying attention to the predicaments of precarity.